He can never explain why he's still traveling if he hates it so much, but he'll spend hours talking your ear off while he points out how good things used to be. This is the person who for years tells everyone he knows how great a country is and then gets pissed that a bunch of people decided to actually go.
He's depressing and obnoxious, and you don't need to listen to him since you're here at the destination -- now, not 10 years ago. Focus on making this the moment to yearn for, the moment that will make people jealous for years. Focus on making right now the best time as it's ever been to be where you are.
We all have dietary restrictions and preferences, but trying new food is an essential part of the travel experience. When someone invites you into their home to share their local cuisine, eat it. Even if it looks like death and smells like death's morning breath, eat it.
There's nothing worse than traveling with people who won't eat the native food because they think it's gross (though, of course, they have never tried it). It's simply awful watching them insult your new friends by saying, "I just don't eat that kind of food," as if the local food is beneath their own familiar cuisine. And when they look at a menu in China and ask, "Do they have burgers here?" you can't help but think to yourself, "Why the f**k did you leave home if all you want to do is eat your own food?!"
Ryan McVay/Photodisc/Getty Images
"You know what they say: When in Rome, eat the cheeseburgers."